TEHRAN, Iran — Iran's president on Wednesday accused European diplomats and protesters who disrupted his recent attack on Israel at a U.N. conference of trying to muzzle anyone who says "a word against the racism of the Zionist regime."

President Mahmoud Ahmadinejad reiterated the criticism of Israel in his first comments on the incident at a racism conference in Geneva on Monday. Protesters in rainbow-colored wigs lobbed red clown noses at him and EU representatives walked out of the speech when he called Israel the "most cruel and repressive racist regime."

Ahmadinejad, who is running for another term in Iran's June 12 presidential election, is a deeply polarizing figure who has called for Israel to be wiped off the map, denied the Holocaust and insists Iran will never give up uranium enrichment.

His latest attacks on Israel came at a moment when the Obama administration was reaching out to Iran to start a dialogue after decades of political deadlock. Though he has expressed a willingness for a new start with the U.S., his animosity toward one of Washington's closest allies in the region only complicates the relationship.

Western suspicion that Iran's nuclear program is geared toward making weapons is one of the biggest sources of tension. Iran's official news agency said Wednesday the country welcomes a "constructive" dialogue with world powers over its nuclear program but insisted it won't halt uranium enrichment.

Enriched uranium can be used as a fuel for both nuclear power and nuclear weapons, but Iran insists its program is for peaceful purposes.

Last week, Ahmadinejad said Iran was preparing a new package of proposals aimed at resolving the nuclear dispute with the West but offered no details.

Speech divisive, Ban saysSecretary of State Hillary Rodham Clinton said Wednesday that by trying to talk Iran out of its nuclear program, the United States is in a better position to organize tougher international sanctions should diplomacy fail.

"We actually believe that by following the diplomatic path we are on, we gain credibility and influence with a number of nations who would have to participate in order to make the sanctions regime as tight and as crippling as we would want it to be," Clinton told the House Foreign Affairs Committee.

The U.N. Security Council has already imposed three rounds of sanctions on Iran for its failure to suspend uranium enrichment, but the U.S. has faced resistance from Russia and China to add more.

The U.S. skipped the U.N. racism conference in Geneva out of concern it would focus largely on Israel at the expense of other issues.

U.N. Secretary General Ban Ki-moon said he was disappointed Ahmadinejad's speech was used "to accuse, divide and even incite," directly opposing the aim of the meeting.

But the U.N. said the hard-line Iranian president had actually dropped language from the speech that described the Holocaust as "ambiguous and dubious."

Ahmadinejad may have decided to drop the Holocaust phrase that was in his original text to deliver his condemnation of Israel in a more palatable fashion for many countries.

He said Wednesday on Iranian state television that the diplomats and protesters who disrupted his speech "were intending to disturb the conference so that no one would be able to say a word against the racism of the Zionist regime."

Mir Hossein Mousavi, the leading reformist candidate challenging Ahmadinejad in June elections, criticized the diplomats' walkout but also held the president responsible for an incident he said undermined "the dignity of Iran and Iranians."